Borrelia Class

Borrelia

Order: SpirochaetalesFamily:: Spirochaetaceae

Genus:: Treponema Borrelia

Family: LeptospiraceaeGenus:: Leptospira

General Overview

• Gram-negative spirochetes

• Spirochete from Greek for “coiled hair”

• Extremely thin and can be very long

• Tightly coiled helical cells with tapered ends

• Motile by periplasmic flagella (endoflagella)

Endoflagella

Borrelia

• Large, 5-30 um long & 0.3-.7 um wide

• Motile with endoflagella

• Readily stained by ordinary methods – Gram negative

• Irregular, wide open coils.

• Commensals in buccal & genital mucosa

Treponema Leptospira

Borrelia

Spirochaetales Associated Human Diseases

Genus Species Disease

Treponema pallidum ssp. pallidum

pallidum ssp. endemicum

pallidum ssp. pertenue

carateum

Syphilis

Bejel

Yaws

Pinta

Borrelia burgdorferi

recurrentis

Many species

vincenti

Lyme disease (borreliosis)

Epidemic relapsing fever

Endemic relapsing fever

Vincent’s angina

Leptospira interrogans Leptospirosis

(Weil’s Disease)

Lyme Disease

History

• Lyme, Connecticut, USA. – in 1975

• In a cluster of suspected Juvenile Rheumatoid

arthritis.

• Five years later, Burgdoofer identified the

organism.

Epidemiology

Causative organism: B.burgdorferi

Vector : Ixodid ticks

Reservoir: Deer &

small mammals

Morphology

• 4-5 * 0.2-0.25 um

• Flexible, helical

• Gram negative

Species

• B.burgdorferi

• B.garinii

• B.afzelii

Culture

• Fastidious

• Modified Kelly’s (BSK) medium

• Incubation at 33 degree for > 2 wks.

Clinical features

• Incubation period: 3-30 days

• Three stages

1. Erythema migrans

2. Disseminated infection

3. Persistent infection

Erythema migrans

1.ERYTHEMA MIGRANS

• Localised infection

• Expanding annular skin lesion

• Bull’s eye appearance.

1.ERYTHEMA MIGRANS

2. DISSEMINATED INFECTION

• Fever

• Headache

• Myalgia

• Arthralgia

• Lymphadenopathy

• Meningeal & Cardiac involvement

3. PERSISTENT INFECTION

• Chronic arthritis

• Polyneuropathy

• Encephalopathy

• Acrodermatitis

Lab Diagnosis

1. Isolation

1. Ticks

2. Patients – Skin, CSF & Blood

2. Serology

1. ELISA

2. IF

Treatment

• Doxycycline

• Amoxycillin

• Cefuroxime

Relapsing fever

Introduction

• Arthropod-borne infection

• Two types

1. Epidemic RF

2. Endemic RF

Epidemic RF

• B.recurrentis

• Louse-borne

• Pediculus humanus corporis (body lice)

• No extra-human reservoir.

Endemic RF

Causative agents:

1. B.duttonii

2. B.hermsii

3. B.parkeri

• Tick-borne

• Reservoir – Rodents & other mammals

Morphology

• 8-20 um * 0.2-0.4 um

• Irregular spirals with one or both ends pointed

• 5-10 loose spiral coils

• Gram negative

• Giemsa staining

Cultural characteristics• Microaerophilic

• Cultivation is difficult in medias

• Egg inoculation in chick embryos

• Chorioallantoic membrane

• Animal inoculation - intraperitoneal

• Rat

•Mice

Antigenic variation

• Readily undergoes antigenic variations in vivo

• DNA rearrangement in linear plasmids

• Ultimate recovery – development of immunity

to all the antigenic variants.

Clinical features

• Incubation period: 2-10 days

Sudden onset of fever (3-5 days)

Afebrile period for 4-10 days

Another bout of fever

• Subsides after 3-10 relapses.

Relapsing fever

Epidemiology- Epidemic Relapsing Fever

• Transmitted person-to-person by human body lice

(vectors) from infected human reservoir

• Infect host only when louse is injured, e.g., during

scratching

• A single louse can only infect a single person

• Lice leave host that develops a fever and seek

normal temperature host

Epidemiology- Endemic Relapsing Fever

• Sporadic cases

• Transmitted by soft body ticks (vectors) from

small mammal reservoir

• Ticks can multiply and infect new human

hosts

Lab Diagnosis

• Wet film

• Lashing motility

• Blood smears

•Giemsa stain

• Leishman stain

•Dilute carbol fuchsin

• During pyrexial period

Giemsa Stain of Borrelia recurrentis in Blood

Light Microscopy Phase Contrast Microscopy

Lab Diagnosis

• Animal inoculation

- White mice

- Intraperitoneal

• Serology

- Agglutinins for Proteus OXK

Treatment

• Tetracyclines

• Chloramphenicol

• Penicillin

• Erythromycin

Borrelia vincenti

• Fusospirochetosis

• B.vincenti

• Fusobacterium fusiforme

• Ulcerative gingivostomatitis

• Oropharyngitis (Vincent’s angina)

• Lung abscess

• Gangrenous balanitis

Vincent’s angina

Borrelia recurrentis

Borrelia spp.

Borrelia burgdorferi

Summary